EDEN PRAIRIE, Minn. -- If Leslie Frazier's stint as Minnesota Vikings interim coach is about learning on the job, this week's lesson will be game-day roster decisions.

Three starters -- running back Adrian Peterson (ankle sprain), end Ray Edwards (high ankle sprain) and guard Steve Hutchinson (broken thumb) -- will work out before Sunday's game against Buffalo to determine whether they'll suit up, Frazier said, while starting receiver Percy Harvin's status is up in the air because of his latest bout with migraine-related problems.

The entire group, along with backup receiver Greg Lewis (concussion) and safety Jamarca Sanford (hamstring), was listed as questionable on Friday's injury report.

However, Peterson looks like the best bet to play and was the only one of the four starters who got any significant work in practice this week.

"Moved around pretty good," Frazier said after Peterson returned to practice on Friday. "There's a probability that he will be able to play. We're going still take him out on Sunday morning, just to see how he moves around, make sure he's confident in what he has to do to play in the game. He did a much better job than we though he would (Friday), so we're optimistic."

Edwards and Hutchinson mostly were spectators during Friday's workout -- Edwards was listed as a limited participant on the injury report -- and Frazier painted a dim picture of Edwards' chances for playing. Hutchinson has "gained a little bit more confidence about what he can and can't do" with a cast and wrap on the thumb, Frazier said, but like the others, he'll be a game-day decision.

Frazier confirmed Harvin went to the doctor on Friday and said the second-year receiver felt better than he had since falling ill during Wednesday's practice. That wasn't enough to get him back on the field as hoped, though.

Shortly after his August collapse from an allergic reaction to medication, Harvin expressed confidence that doctors had pinpointed the root of the migraines, but the problem hasn't abated.

"There are a lot of things that will have to be addressed, because you hate to see him going through what he's going through," Frazier said. "Just hoping that this offseason at some point soon we can come to some conclusions that will help not to have to deal with this for the rest of his life. It's just a lot of things that we've got to go through."

The only player ruled out for Sunday is cornerback Chris Cook, whose surgically repaired knees "still aren't where they need to be, so we're to shut him down in order to buy him a little time." Asked to clarify, Frazier said Cook has been shut down for this week, not the entire season.

"Just advice that we got from the doctors where he needs to rest," Frazier said. "He needs to get off his legs, so that's what we're going to do. Try to get him back next week."